<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title></title>
    <style>
        html,
        body {
            /* 核心属性 让页面平滑滚动*/
            scroll-behavior: smooth;
        }

        #one,
        #two,
        #three {
            width: 80%;
            height: 700px;
            background-color: #eee;
            margin: 50px auto;
            font-size: 50px;
            text-align: center;
            line-height: 700px;
        }

        /* 定位置顶按钮 */
        .backToTop {
            position: fixed;
            right: 20px;
            bottom: 100px;
            background-color: red;
            text-align: center;
            line-height: 60px;
            width: 60px;
            border-radius: 5px;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
            transition: background-color 0.3s ease;
        }

        .backToTop:hover {
            background-color: darkred;
        }

        .navigation {
            position: fixed;
            right: 20px;
            bottom: 200px;
        }

        a {
            display: block;
            text-align: center;
            line-height: 60px;
            width: 60px;
            color: aliceblue;
            text-decoration: none;
            margin-bottom: 10px;
            background-color: skyblue;
            border-radius: 5px;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
            transition: background-color 0.3s ease;
        }

        a:hover {
            background-color: dodgerblue;
        }
    </style>
</head>
<body>
    <section id="one">模块1</section>
    <section id="two">模块2</section>
    <section id="three">模块3</section>
    
    <div class="navigation">
        <a href="#one">01</a>
        <a href="#two">02</a>
        <a href="#three">03</a>
    </div>
    
    <a href="#one" class="backToTop">
        置顶
    </a>
</body>
</html>